avian_pickup 0.5.0

//! A little minigame where you and an NPC play catch with a box.
//! Shows how to use two different actors with Avian Pickup:
//! one is the player, and the other is an NPC.

use std::f32::consts::{FRAC_PI_2, FRAC_PI_6, PI};

use avian_pickup::prelude::*;
use avian3d::prelude::*;
use bevy::{color::palettes::tailwind, input::mouse::AccumulatedMouseMotion, prelude::*};
use rand::Rng;

mod util;

fn main() {
    App::new()
        .add_plugins((
            DefaultPlugins,
            PhysicsPlugins::default(),
            AvianPickupPlugin::default(),
            // This is just here to make the example look a bit nicer.
            util::plugin(util::Example::Resettable),
        ))
        .add_systems(Startup, setup)
        // Pass input to systems runing in the fixed update.
        // Input handling and camera movement need to be executed every frame,
        // so we run them in a variable timestep.
        // We also want them to happen before the physics system, so we add them
        // to the last variable timestep schedule before the fixed timestep systems run.
        .add_systems(
            RunFixedMainLoop,
            (
                on_reset_pressed,
                handle_input,
                make_npc_catch,
                rotate_camera,
            )
                .in_set(RunFixedMainLoopSystems::BeforeFixedMainLoop),
        )
        // Run fixed update zero to many times per frame.
        .add_systems(
            PhysicsSchedule,
            (tick_timer, rotate_npc)
                .chain()
                .in_set(AvianPickupSystem::First),
        )
        // React to things that happened during the fixed update.
        .add_systems(
            RunFixedMainLoop,
            (on_npc_hold, on_player_throw, on_aim_timer)
                .in_set(RunFixedMainLoopSystems::AfterFixedMainLoop),
        )
        .run();
}

#[derive(Debug, Component)]
struct Prop;

#[derive(Debug, Component)]
struct Player;

#[derive(Debug, Clone, Default, Component)]
struct Npc {
    state: NpcState,
    timer: Timer,
}

#[derive(Debug, Clone, Copy, Default, Component)]
enum NpcState {
    #[default]
    Waiting,
    Catching,
    Aiming(Vec3),
}

impl Npc {
    const AIM_DURATION: f32 = 1.0;

    fn waiting(&mut self) {
        self.state = NpcState::Waiting;
        self.timer = Timer::default();
    }

    fn aiming_to(&mut self, dir: Vec3) {
        self.state = NpcState::Aiming(dir);
        self.timer = Timer::from_seconds(Self::AIM_DURATION, TimerMode::Once);
    }

    fn catching(&mut self) {
        self.state = NpcState::Catching;
        self.timer = Timer::default();
    }
}

const INITIAL_BOX_TRANSFORM: Transform = Transform::from_translation(Vec3::new(0.0, 2.0, 2.0));

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    let terrain_material = materials.add(Color::WHITE);
    let npc_material = materials.add(Color::from(tailwind::LIME_300));
    let visor_material = materials.add(Color::from(tailwind::LIME_600));
    let prop_material = materials.add(Color::from(tailwind::ORANGE_300));

    // let's boost the default values a bit to make this more fun :)
    let actor_config = AvianPickupActor {
        interaction_distance: 3.0,
        throw: AvianPickupActorThrowConfig {
            linear_speed_range: 0.0..=10.0,
            ..default()
        },
        ..default()
    };

    commands.spawn((
        Name::new("Player Camera"),
        Camera3d::default(),
        Transform::from_xyz(0.0, 1.0, 5.0),
        actor_config.clone(),
        Player,
    ));

    let npc_shape = Sphere::new(0.7);
    let visor_shape = Cuboid::from_size(Vec3::new(1.0, 0.5, 0.01));
    commands
        .spawn((
            Name::new("NPC"),
            Mesh3d::from(meshes.add(Mesh::from(npc_shape))),
            MeshMaterial3d::from(npc_material.clone()),
            Transform::from_xyz(0.0, 1.0, -5.0).looking_to(Vec3::Z, Vec3::Y),
            actor_config,
            Npc::default(),
        ))
        .with_children(|parent| {
            parent.spawn((
                Name::new("Visor"),
                Mesh3d::from(meshes.add(Mesh::from(visor_shape))),
                MeshMaterial3d::from(visor_material.clone()),
                Transform::from_xyz(0.0, 0.0, -0.71),
            ));
        });

    commands.spawn((
        Name::new("Light"),
        Transform::from_xyz(3.0, 8.0, 3.0),
        PointLight {
            color: Color::WHITE,
            intensity: 2_000_000.0,
            shadows_enabled: true,
            ..default()
        },
    ));

    let ground_shape = Cuboid::new(15.0, 0.25, 15.0);
    let ground_mesh = meshes.add(Mesh::from(ground_shape));
    let terrain_transforms = [
        Transform::default(),
        Transform::from_xyz(7.5, 0.0, 0.0).with_rotation(Quat::from_rotation_z(FRAC_PI_2)),
        Transform::from_xyz(-7.5, 0.0, 0.0).with_rotation(Quat::from_rotation_z(FRAC_PI_2)),
        Transform::from_xyz(0.0, 0.0, 7.5).with_rotation(Quat::from_rotation_x(FRAC_PI_2)),
        Transform::from_xyz(0.0, 0.0, -7.5).with_rotation(Quat::from_rotation_x(FRAC_PI_2)),
    ];
    for (i, transform) in terrain_transforms.iter().enumerate() {
        commands.spawn((
            Name::new(format!("Wall {}", i)),
            Mesh3d::from(ground_mesh.clone()),
            MeshMaterial3d::from(terrain_material.clone()),
            *transform,
            RigidBody::Static,
            Collider::from(ground_shape),
        ));
    }

    let box_shape = Cuboid::from_size(Vec3::splat(0.5));
    commands.spawn((
        Name::new("Box"),
        Mesh3d::from(meshes.add(Mesh::from(box_shape))),
        MeshMaterial3d::from(prop_material.clone()),
        INITIAL_BOX_TRANSFORM,
        RigidBody::Dynamic,
        Collider::from(box_shape),
        Prop,
        // Because we are moving the camera independently of the physics system,
        // interpolation is needed to prevent jittering.
        TransformInterpolation,
    ));
}

fn handle_input(
    mut avian_pickup_input_writer: MessageWriter<AvianPickupInput>,
    key_input: Res<ButtonInput<MouseButton>>,
    players: Query<Entity, (With<AvianPickupActor>, With<Player>)>,
) {
    for player in &players {
        if key_input.just_pressed(MouseButton::Left) {
            avian_pickup_input_writer.write(AvianPickupInput {
                action: AvianPickupAction::Throw,
                actor: player,
            });
        }
        if key_input.just_pressed(MouseButton::Right) {
            avian_pickup_input_writer.write(AvianPickupInput {
                action: AvianPickupAction::Drop,
                actor: player,
            });
        }
        if key_input.pressed(MouseButton::Right) {
            avian_pickup_input_writer.write(AvianPickupInput {
                action: AvianPickupAction::Pull,
                actor: player,
            });
        }
    }
}

fn rotate_camera(
    accumulated_mouse_motion: Res<AccumulatedMouseMotion>,
    mut transform: Single<&mut Transform, With<Camera>>,
) {
    // The factors are just arbitrary mouse sensitivity values.
    let camera_sensitivity = Vec2::new(0.001, 0.001);

    let delta = accumulated_mouse_motion.delta;
    let delta_yaw = -delta.x * camera_sensitivity.x;
    let delta_pitch = -delta.y * camera_sensitivity.y;

    let (yaw, pitch, roll) = transform.rotation.to_euler(EulerRot::YXZ);
    let yaw = yaw + delta_yaw;

    const PITCH_LIMIT: f32 = FRAC_PI_2 - 0.01;
    let pitch = (pitch + delta_pitch).clamp(-PITCH_LIMIT, PITCH_LIMIT);

    transform.rotation = Quat::from_euler(EulerRot::YXZ, yaw, pitch, roll);
}

fn rotate_npc(
    time: Res<Time>,
    mut npcs: Query<(&mut Transform, &Npc)>,
    prop: Single<&Transform, (With<Prop>, Without<Npc>)>,
) {
    let dt = time.delta_secs();

    for (mut transform, npc) in &mut npcs {
        let dir = match npc.state {
            NpcState::Waiting | NpcState::Catching => prop.translation - transform.translation,
            NpcState::Aiming(dir) => dir,
        };
        let target = transform.looking_to(dir, Vec3::Y);
        let decay_rate = f32::ln(30.0);
        transform.rotation = transform
            .rotation
            .slerp(target.rotation, 1.0 - f32::exp(-decay_rate * dt));
    }
}

fn tick_timer(time: Res<Time>, mut npcs: Query<&mut Npc>) {
    for mut npc in &mut npcs {
        npc.timer.tick(time.delta());
    }
}

fn make_npc_catch(
    mut npcs: Query<(Entity, &Npc)>,
    mut avian_pickup_input_writer: MessageWriter<AvianPickupInput>,
) {
    for (entity, npc) in &mut npcs {
        if !matches!(npc.state, NpcState::Catching) {
            continue;
        }
        avian_pickup_input_writer.write(AvianPickupInput {
            action: AvianPickupAction::Pull,
            actor: entity,
        });
    }
}

fn on_npc_hold(
    mut npcs: Query<(&mut Npc, &AvianPickupActorState), Changed<AvianPickupActorState>>,
) {
    for (mut npc, state) in &mut npcs {
        if !matches!(state, AvianPickupActorState::Holding(..)) {
            continue;
        }
        let mut rng = rand::rng();
        let min_pitch = -FRAC_PI_6;
        let max_pitch = 0.0;
        let min_yaw = -PI / 12.0;
        let max_yaw = PI / 12.0;
        let random_pitch = rng.random_range(min_pitch..max_pitch);
        let random_yaw = rng.random_range(min_yaw..max_yaw);
        let rotation = Quat::from_euler(EulerRot::YXZ, random_yaw, random_pitch, 0.0);
        let dir = rotation.mul_vec3(Vec3::Z);
        npc.aiming_to(dir);
    }
}

fn on_aim_timer(
    mut npcs: Query<(Entity, &mut Npc)>,
    mut avian_pickup_input_writer: MessageWriter<AvianPickupInput>,
) {
    for (entity, mut npc) in &mut npcs {
        if !matches!(npc.state, NpcState::Aiming(..)) || !npc.timer.is_finished() {
            continue;
        }
        npc.waiting();
        avian_pickup_input_writer.write(AvianPickupInput {
            action: AvianPickupAction::Throw,
            actor: entity,
        });
    }
}

fn on_reset_pressed(
    mut npcs: Query<(&mut Npc, &mut AvianPickupActorState)>,
    mut props: Query<(&mut Transform, &mut LinearVelocity, &mut AngularVelocity), With<Prop>>,
    key_input: Res<ButtonInput<KeyCode>>,
) {
    if !key_input.just_pressed(KeyCode::KeyR) {
        return;
    }
    for (mut npc, mut state) in &mut npcs {
        if matches!(npc.state, NpcState::Aiming(..)) {
            continue;
        }
        npc.waiting();
        *state = AvianPickupActorState::Idle;
        for (mut transform, mut vel, mut angvel) in &mut props {
            *transform = INITIAL_BOX_TRANSFORM;
            vel.0 = Vec3::ZERO;
            angvel.0 = Vec3::ZERO;
        }
    }
}

fn on_player_throw(
    mut throw_events: MessageReader<PropThrown>,
    mut npcs: Query<&mut Npc>,
    players: Query<(), With<Player>>,
) {
    for event in throw_events.read() {
        if players.contains(event.actor) {
            for mut npc in &mut npcs {
                npc.catching();
            }
        }
    }
}